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# Value Sources (API, Oracle)

**`set_collection_value_source(...)`**: Assigns an API endpoint or oracle address as the value source.

When **`is_api_source = true`**, metadata or NFT values may depend on data fetched from this endpoint.

When **`is_api_source = false`**, the source is considered an oracle address providing on-chain data feeds.

This feature enables dynamic NFTs that can reflect external states or real-world conditions.